Garudapurana 1.218.18

1.218.18

tato viparītopavītena savyañjanaṃ saghṛtamannaṃ pitrādi brāhmaṇapātre nidhāya tadupari bhūmisaṃlagnakuśaṃ dattvā oṃ pṛthivī te pātraṃ iti mantreṇa uttānābhyāṃ pātraṃ gṛhītvā oṃ idaṃ viṣṇorityannopari uttānaṃ dvijāṅguṣṭhaṃ niveśayet /
oṃ apahateti tilavikiraṇam /
bhūmipātitavāmajānuḥ amukagotrebhyaḥ asmatpitṛpitāmahebhyaḥ sapatnīkebhyaḥ etadannaṃ saghṛtaṃ sapānīyaṃ savyañjanaṃ pratiṣiddhavarjitaṃ svadhā /
annaṃ saṅkalpya oṃ ūrjaṃ vahantīramṛtaṃ ghṛta payaḥ kīlālaṃ paristrutaṃ svadhāstu tarpayata me pitaram /
dakṣiṇāmukhavaridhāratyāgaḥ //

Then, wearing the sacred thread over the right shoulder, having placed food with condiments and clarified butter in the vessel of the brāhmaṇa [representing] the ancestors, and having placed kuśa grass touching the ground upon it, holding the vessel with upturned hands with the mantra: 'Oṃ, the earth is your vessel,' one should place the upturned thumb of the brāhmaṇa upon the food with: 'Oṃ, this Viṣṇu [strode].' / Scattering of sesame seeds with: 'Oṃ, struck away [are the demons].' / Having dropped the left knee to the ground: 'To our fathers and grandfathers of such-and-such gotra, together with their wives, this food with clarified butter, water, and condiments, free of what is forbidden, svadhā!' / Having dedicated the food: 'Oṃ, bearing nourishment, ambrosia, clarified butter, milk, sweet drink, and foaming liquor, let there be svadhā; satisfy my father!' / The pouring of a stream of water facing the south.